Atrial fibrillation (AF) is the most common type of tachyarrhythmia encountered in clinical practice. Pulmonary vein isolation (PVI) has become the mainstream catheter ablation technique for AF. For persistent AF, substrate modification with complex fractionated electrogram (CFE) ablation is considered to be necessary to patients who have not responded to PVI.
Conventional AF identification methods include dominant frequency (DF) analyses in frequency domain of consecutive electrograms, and CFE mean analysis in time domain of consecutive electrograms. Both methods produce average results based on activation intervals, which not applicable to diagnosing persistent or late stage AF patients. In particular, CFEs are usually observed in many regions of the atria, which make it difficult to identify critical atrial substrate using the conventional AF identification methods.
There is therefore a need to more accurate identification of critical regions and discriminate them from by-standers than conventional AF identification methods.